This invention aims to be another improvement in the field of “Self-Supported Rotating Rigs”, calling by this name those sailing rigs in which the mainsail boom extends in front of the mast, bending a self-tacking jib to this common boom (5), rotating the whole set of: mast (1), boom and sails simultaneously around a sensibly vertical axis, and being the whole rig supported by a rotating rig connection (6) to the boat's hull without having to use shrouds or stays (FIG. 1).
Among others, this type of rigs has been already used in 1975 by K. R. May under the name of Boomsprit and later by Carbospars Ltd under the name Aero-Rig.
In 1999 we, Inversail, S. A., disclosed a new rig, much improved, under the name of Spindle-Rig, filing the corresponding patent application: “Improvements to rotary gear for sailing boats” (WO 0104000). (FIGS. 2, 3 and 4). Characteristics of this rig were: A platform (2) at the base of the rig, next to the ship's deck, which allowed the rig's rotation control, and rotating shrouds (15) which from the said platform permitted the stabilization of the mast. Another important feature of this rig was the use of two wishbone-type booms (16), one for the mainsails (3) and another one for the jib (4), being these booms hinged connected (28) to a first crosstree (12) placed above people's heads, which permitted the independent up and down movement of the mainsail boom, and also that the sails could come down even to deck level, thus lowering the centre of effort and making the sails more accessible.
Nevertheless, when we started the development and building of this rig we realized that the wishbone booms and their hinged connection to the first crosstree was not a good solution because the enormous horizontal rotating torques created by the wind in both booms had to be absorbed through this delicate connection. Also access to the said booms was rather difficult when reefing and especially in emergency situations.